Fluid-translating device



Sept. '29, 1925. 1,555,030

H. F. SCHMIDT FLUID TRANSLAIING DEVICE Original Filed Sept. 14', .1914 2 Sheets-Sheet l INVENTOR ATTORNEY HenryF. Schmidt Sept. 29, 1925.

IIIIIIIIII 1,555,030 H. F. SCHMIDT FLUID TRANSLATING DEVICE :2 ,Sheets- Sheet 2 Original Filed Sept. 14, 1914 II I f 9mm ATTORNEY I kg HemyESchmid'l INVENTOR Patented Sept, 29;, 1925;

HENRY I. SCHMIDT, OF BWARTHHORE, PENNSYLVANIA, ASSIGNOR T6 WESTING- HOUSE ELECTRIC HANUFAGTURIIIG COMPANY, A CORPORATION OF PENNSYL- vurm I'LTl'ID-TBANSLATING DEVICE.

brim! application filed September 14, 1914; Serial 80.861329. Divided and tliil application filed December 80, 1921, Serial No. 525,822. Renewed February 27,1924.

Tub-all whom'it may concern.

Be it'known that 'I, HENRY FKSCHMIDF, a citizen of the United States, and a resident of Swarthmore, in the county of Delaware and State of Pennsylvania, have invented a new and useful lmprovementin Fluid-Translating Devices, of which the following is a specification, this application being a division of my application, Serial No. 861,629, filed Sept. 1a, 1914.

-'lhis invention relates to fluid translating devices and particularly-to devices tor flit tilt

- I iliustratedin Fig. 2.

maintaining a high vacuum. in condensers or similar apparatus. v

An ohyect of the invention is to produce a fluid translating device of the kinetic type in which means are employed for maintaining the operation of the device substantially constant forkpractically all varying condi tions.

A further ohject is to produce a fluid translating" device employing the kinetic or velocity energy oi the motive fluid delivered to it in transiterring fluid from a region oilower to a region of higher pressure, which automatically adjusts itseli to variations'in the quantity oi fluidconveyed, thus preventing; fluctuations of pressure in either the region of lower or higher pressure.

These and other objects, which will he made apparent to those 'slrilledin the art throughout the description of vthe invention, are attained by apparatus emhodyingthe features herein described and illustrated in the drawings accompanying and forming" a part of this application. "in the drawlngsz Fig.1 is a more or less diagrammatic sectional view of a fluid translating device or ejector embodying my invention.

Fig. 2 is a sectlonal' view which embodies t a modification out my invention.

Fig. 3 is a diagratic sectional view of a relay mechanism which may he employed in carrying out my invention.

Fig. 4 is a dia rammatic sectional view of a dash pot whic may be employed in con-,

nection with the apparatus illustrated in Fig. 1.

ig; 5 is a diagrammatic sectional view of a relay mechanism which may be emloyed in connection with the apparatus all varying F1 2. i I r a c %n fluid translating devices such," for example, as e'ectors, which employ a stream orjet of fiuld as the propelling medium for exhausting fluid'from .a receptacle, or for transferrin fluid from a region of lower to a region 0 hi her pressure, it is necessary to construct t e fluid conducting passage, through which the propelling medium and the medium entrained move in accordance with the following equation:

All

ve-" W,

in which it equals the cross sectional area out the tube at any point; 'V the velocity of the combined media assing that oint; o the specific volume of and W a constant which is equal to the weight of the media passing the point, in a unit of time. c

it will he apparent, therefore, that it the the comloine media;

fluid translatin device or ejector is designed to attain a hi 1 degree out com ression un der one set o operating conditions, it will not be suitable for starting or for operating under varying conditions. in order, therefore, to render the e ector reflective for conditions, it is necessary to vary the dimension oi the fluid conducting or delivering assage in accordance with variations in conditions, or to edect a chan ,e, which is the equivalent of changing the imensions oi the passage to meet the varying conditions.

in the present application ll have lllustrated eiectors in which means are employed or va ing the eflective area of the throat of the 'uid delivering passage or diduser in response to variations in the volume of fluid passin from the region of lower pressure throng the diduser to the outlet, or to the region ot higher pressure. It is well known that the pressures existing throughout the did'user vary in response to variations in the amount of fluid traversing the difiuser, and

it is also well known that in order to prevent u settin when the ejector is operating'un er lip; t load, or at less than its designed capacity, it is necessary thatthe or passage 5. The passage is adapte to communicate with'a condenser or a receptacle from which fluid or medium is to be withdrawn. The chamber 4 is also provided with one or more fluid delivery nozzles' 6 of any suitable design, but preferably converging-divergin nozzles which are adapted to receive igh pressure fluid, for example, steam, and after expanding it to the pressure existin in the chamber 4 to discharge it throng the diffuser 3. The nozzles,.-if more than one is em loyed, are so arrangedthat in dischar ing tihroughthe chamber 4 and into the di user 3 the entrain the fluid or medium in' the cham er 4 le stream which enifluser and traverses and with it form a sin ters the throat of the thedifiuser.

30 Since, in order to provide an. effective eilector, .it is necessary that the product of t e area of the conducting passage and the velocity of the medium divided by the spe- OlfiC vo ume of the medium shall e ual a constant, which is the weight of me iuin passing through the e'ector in a unit of time, since it also is desirable to maintain a constant pressure in thechamber 4, the specific volume of the medium will therefore be maintained constant; and since the nozzle or nozzles'6 discharge from a constant initial to a constant final ressure, i. e., the ressure 1n the chamber 4, 1t is evident that,'1n order; to maintain a condition ofstable e uilibrium 1n the diffuser, the area of the di user must be varied in direct proportion to the variatlons'in the weight of themedium passing throu h it.

-, ing while specific volume of the If t e area of the throat of the diffuser is not varied, as above set forth, it is-evident that, since the weight of the medium is vary medium of the chamber 4 remains constant the velocity of the medium passing through the throat must vary, that 1s, decrease if the weight of medium passing decreases, and increase if the weight of medium passm increases. In

'order to compress or disc 'arge medium fromthe chamber 4 through-the outlet of the diffuser 3, a definite amount of work per umt weight of medium must be performed,

, and this work of compression or translation must be provided by thekinetic energy of the mediumat the entrance of the di user. Consequently the velocity of the medium means which corres onds in its op- .the differential pressure sequently when the at the entrance decreases so that the kinetic energy of the medium is less than the work necessary to move' the medium from the lowerto the higher pressure, it is apparent that the medium will not be discharged from the outlet of the diffuser. Under such conditions the velocity of the medium in the diffuser will immediately drop to zero, and not only no work of compression will be accomplished, but fluid will flow from the region of higherpressure or the outlet end of the diffuser into the region of lower pressure, or the chamber 4. This result is technically known as upsetting, towhich reference has been previously made. a

The present-embodiment of my invention includes a conical plug 7, which extends axially of the difiuser 3-- and is movable longitudinally-by a piston 8, in such a manner as to increase or decrease the effective area of the throat of thedifi'user and thereby maintain a constant velocity of the medium through the throat so as to'maintain v a condition of eiuilibrium for all rates of fluid or medium elivery;

.The piston 8 is mounted in a cylinder 9,' to one end of which, as for example above some point along the difiuser, is transmitted through a pipe or passage vide some means, such for exam Is, as a light coiled spring 12, for yielding y resisting movement of the piston in'response to a pre onderance of pressure] introduced .throug the pipe 11.

The spring serves the purpose of insuring a definite position of the piston 8, and consequently ofthe plug 7 for each increment of pressure variation in point of communication with the pipe '11. With this arrangement, the plug 7 W111 move to different positions 1n response to variations in the relative pressures in the chamber 4; and the point 0 communication of the pipe 11 with the diffuser, and will thereore proportion the efi'ective throat of the difiu'ser, in accordance with variations in the amount of fluid traversing the diffuser. It will, of course, be understood that the ress'ure in the diffuser 3 will always be igher than the pressure in the inlet chamber a when the ejector is in operation. How ever, the pressure ratio,

acting on the piston 8,-will vary as the densit in the chamber a varies. en starting up the pressure in the diffuser will preponderate over the pressure in the inlet chamber to a much greater extent than when a partial vacuum is established in the chamber goons c. H

rpiantity of medium to t eplunger 7 is raised,

be removed is large 11. I also pro-' ion the diffuser 3 at the I or; 1n other words,

of the medium and when 'the quantityto be removed is small the lunger 7 is lowered.

It will understood that the apparatus of Fig. l is merely illustrative, and that under ordinary working conditions, the difference in pressure existing-in the cylinder 9 above and below the iston 8 may not be suiiicient to overcome riction' and the inertia of the arts and to insure the pro or operation of' t e plug 7. It may there ore be desirable to connect the pi 's 10 and 11 to the operating cylinder 0 a lightand sensitive relay, which will control the delivery of operating medium to the cylinder 9 in responseto variations in the pressure differences between the chamber 4 and the difi user It will also be apparent that under ordinaryconditions it will be desirable to employ some means, such for example as a dash pot, for preventing the slight fluctuations in pressure within the 'difluser 3 from affecting the operation of the plug 7; and

I that the dash pot may he operatively contill nected to either the relay or to the piston 8. In Fig. 3 l have shown a relay mecha nism which may he employed in controlling the piston 8 and-hence the plug 7. As illustrated, this mechanism comprises a'cylinder 20 in which a piston 21 operates in response to variations in pressure. in the two pipes l0 and ll which connect the ejector inlet 5 and the difiuser 3' with opposite ends or.

the cylinderfll. A pilot valve 22 is shdwn as adapted to lee-operated by the piston 21 and controls the delivery of afrelntively high pressure actuating lluid to and from the cylinder 9 through thepi es l0 and i0. llctuoting fluid, prelerah y oil, may to supplied tothe pilot valve by means oil a pipe 533, and is carried oh hy means oat exhaust pipes 2i and 25. l have also shown a piston 26 connected to the piston ill for preventing slight fluctuations in pressure from adecting the operation of the piston ill. The piston 26 loosely fits in a closed cylinder 27., or may he provided with a restricted hole or passageway so as to allow a liinited flow ol-fluid'past the piston so that it may move only under the influence ot a force oi "'reasonahle duration.

in Fig. i, l have shown-n dash pot as connected directly to the plug-controlling piston s in order. to revent movements in responseto minor an discontinuous fluctu: ations in the pressures. its shown, the dash pot consists oil a iston 28 having a restricted opening or y-pass 29 and-adapted iii) to'slide in a cylinder 31). The cylinder 30 he filled with oil or any other fluid.

Fig: 2 l have shown an embodiment of m iny'ention in which a sin le nozzle 6, for deliveringimpellin flui through the chamber his employe The chamber ,4 is also provided with a-port 5., which is adapted to communicate? with areceptacle to be evacuated and means "are employed for automatically varying the efiective area of the throat or of the entire diffuser which is located in. a cylinder 9' and which is r-i idly secured to the plug 7 The cham er 4 communicating w1th one end of the cylinder 9 through a assage 10, while the other end of the cylinder is open to the atmosphere. Under such conditions the iston'8' will move in response to variations etween atmosphere pressure, as exerted on one side and chamber pressure, as exerted on the other side. A spring 12'', having the-functions of the spring 12 of Fig. l, is also employed lorogposing the motion of the iston occasions by a preponderance of t e atmospheric. pressure over that of the chamloer 4c in the a paratus illustrate inl ig. 1, it may he esiralole to employ a dash pot in connection with the piston 8', and it may also he desirable to operate the plu 7 through the agency of a relay'valve which itselt' operates in response to variations in pressure within the chamber 4.

ln Fig. 5, have shown a relay mecha nism which may he employed "for magnifying the lorce exerted loy the pressure of the fluid in the ejector inlet 5'. As shown,

(ill

In this ap iaratus, lust as a ll sprin 33 inthe other end at the cylinder 31 is adapted tooppose the lorce oi the iluid pressure. The piston 32 actuates a pilot valve 34, which controls the delivcry of relatively high pressure actuating fluid to and from the pin controlling cylinder 9. As illustrate, high pressure lluid, such as oil, may he delivered to the a ipe 3d is adapted to carry away the duid en iausted from the cylinder 9". l have also shown a dash pot connected to the pilot valve 34: for preventing a response to discontinuous an in lo Fig. 6,1 have shown a dash pot which may be employed for steadying the plug inor pressure fluctuations.

lllll pilot value 34:, Toy means of a pipe 3-5, and

controlling piston 8. As" illustrated,, a

hollow stem 38, enclosing the stationary cooling fluid inletn'pipe is attached atone lend to the piston 8 and at the other end to a iston 39; The piston 39 is adapted to sli e in a closed cy inder 40 and is provided with a restricted passageway or bypass 41 for allowing the passage of fluid from one side of the piston 39 to the other l tends axially of under the influence of a reasonable continuous and powerful force.

In the apparatus illustrated in Fig. 2, I have provided means for delivering a cooling medium to the difiuser 3', which consists of a water jacket 14 surrounding the divergent wall of the difluser, and means for introducing cooling water into the interior of.,the plug 7 The water. jacket 14 preferably receives cooling water through a pipe or passage 15 and discharges it through a passage 16. Cooling water is preferably delivered to the apex of the com lcal plug 7 throu h t e plug and enters the plug at its cylinder end. The water discharged from the plug issues through ports 18 and may be discharged fromv the cylinder 9"in any suitable manner.

The object of mtroducing cooling medium to the diffuser is to condense the impelling fluid or steam while it is in motion or as it traverses the diifu'ser. By so doing, the volmany.

be reduced. At

ume per unit of weight ,of the propelling fluid is materially reduced, and therefore the work which it must do to discharge itself against the outlet pressure is reduced, thereby rendering a greater amount of energy available for ex elling the medium from the chamber 4. propelling medium with a lower initial velocity, orcontaining less kinetic energy per unitof weight at the nozzle outlet, is therefore capable of discharging a larger volume or weight of medium from the chamber 4' to the outlet of the diffuser than if it were not condensed or cooled.

Although it is not possible to condence all the motive fluid or steam used as the propelling medium while it is in'motion, if this were possible, it will be readily seen that the resulting water of condensation j would be moving with the velocity of steam discharged from the outlet of the nozzle 6'.

The pressure against which this moving jet of water could discharge itself would be thousand times the pressure a ainst which steam movin at the same-ve ocity could discharge itsel i. a

In the agparatus of Fig. 2 the'plug 7 is not only a apted to vary the efiective'area of the ejector 3', but it may also be soproportioned that it will enter the discharge end of the nozzle 6' and therefore out down the delivery of steam by that nozzle to the ejector. It will be apparent that" chamber 4' decreases, further into the difvolume of fluid is being discharged through the diffuser, and that at a determined pressure within the chamber 4', the amount 0 fluid entrained in the chamber 4' will be so reduced that the volume 0 steamfissuing from the, nozzle 6' may also solute pressure of the the plug 7 will move a pipe 17, which e'xas the abf 861,634, filed Septem this pressure the apex of the plug 7 will enter the nozzle 6' and will start to reduce'the discharge of steam from the nozzle.

Attention is directed to my copending apgleication serially numbered 861,630, filed ptember 14, 1914, and entitled Fluid translating device, in which I have illustrated and claimed an ejecting apparatus consisting of a diffuser communicating with the source of medium to be expelled, a nozzle for delivering expelling or motive fluid into and through the diffuser, and means responsive to variations in the pressures encountered within the ejector or the amount of medium to be ejected for varying the effective area of the nozzle. The apparatus illustrated is a two stage ejector in which the first stage includes the motive fluid delivery nozzle and the difluser above described, and the second stage includes a diffuser and an annular nozzle or annular series of nozzles for delivering expelling or motive fluid into and through the second difi'user. The second difi'usercommunicates with and receives fluid and medium expelled from the first mentioned diffuser.

In my copending application entitled Fluid translating device, Serial No. 861,631, filed September 14, 1914, I have disclosed and claimed an ejector in which the main-nozzle is surrounded by accelerating nozzles. The flow of motive fluid to the ac celerating nozzles is controlled by means responsive to variations in pressure conditions within the ejector, and the position of the main nozzle is similarly controlled. The controlling means described and illustrated is similar to the means, illustrated in Fig. 2 of my a plication, Serial No. 861,633, hereafter re erred to, for controlling the {position of the main nozzle. The delivery 0 motive fluid to the accelerating nozzles of this aplication, No. 861,631, is controlled by ports ormed in a movable tubular extension of the movable main delivery nozzle. W

In my copendin a plication serially numbered 861,633, fi ed eptember 14, 1914 and entitled Fluid translating device, I

. have illustrated, described and claimed a sin 1e stage ejecting device communicating wit a source of medium to be expelled, and a nozzle for deliverin expelling or motive fluid through the di user. The nozzle is capable of movement toward and away from the inlet end of the diffuser and this movemerit is controlled by pressure variations within the ejecting device. Means are also disclosed and claimedforvarying the efiective throat of the movable nozzle in response to variations in the pressure encountered withimthe apparatus.

In my copending. application, Serial No. r 14, 1914and-entitled Fluid translatin illustrated. described'an device, I have claimed 8.1181801)- which medium is to be ejected communicating with a diffuser through which the medium from the passage is expelled. A fluid delivery nozzle delivers expelling fluid through a diffuser and a means responsive to variations in the amount or medium entering thepassage is provided for controlling irect communication between the diffuser and the passage. I have further illustrated and claimed a two-stage ejector in with both stages are provided with inlet members'capable of being laced in communication with a source 0 medium to be expelled. The first stage is shown in open communication with the source of medium to be ex lled, whereas the second sta e is provide with ports located substantial y at .the throat of its converging-diverging diffuser and communicating w1th the source of medium to be expelled through a passage which in eflect forms a b -pass around t e first stageb This passage is provided with a.

valve which operates in response to variations in ressure at the throat of thesecond stage di user and therefore controls the delivery of medium to be expelled to the ports ofthe second stage difiuser.

y In my 00 ending a plication, Serial No 861,635, 'file Septem er 14,, 1914 and em titled Fluid translating device, I have disclosed and claimed a multi-stage ejector in which the diffuser of the final ejector of the series is movable for the urpose ofvar ing the delivery of motive uid through the nozzles of the second stage or the expansion ratio of those nozzles. Inaddition to the above, the application discloses an'd claims a diffuser for the final stage which is movable in response to variations in pressure within the e'e'ctor' for the purpose of delivering fluid rom the' source of medium to be expelled around the initial stage "or stages directly to the final diffuser.

In'my co ending application serially numbered 374,3 1, filed pril 16, 1920, and entitled Fluid translating device, I have illustrated, described and claimed a single stage ejecting devicein which a nozzle head, comprismg. a central nozzle and an annular series of nozzles surrounding and below the central nozzle, is ca able of movement toward and away ,from t e inlet of the diffuser, this movement being controlled by pressure variations within the ejecting device. The nozzle head is also provided .with

ports for fluid to be translated cooperative with the central diffusing nozzle.

In my .copendinig appl' p Fluid translating 'evice filed September 14, 1914;, and serlally numbered 861,629, I

' v have illus'tratedand claimed an ejecting device com risinga difluser provided with a acket t ereabo'ut through which a cooling medium is adapted to be circulated, a nozzle lcation. entitled for delivering expellin 01, motive fluid through the difiuser, an means movable inresponse to variations in the amount of medium to be expelled for varying the effective, area of t e difl'user, said means, as

illustrated, being a hollow movable plug or cone-shaped member through which a cooling' medlum is adapted-to be circulated and which is moved to different positions in relation to the difiuser for the purpose of varying both the effective area of the difiuser and the deliveryof expellingfluid through,

the nozzle; ,The. hollow plug is shown as reasons I have em Ioyed the term fluid "inits broadest sense t roughoutthe entire a plication, since I do not wish to limit .t e lnventlon 'to apparatus employing elther compressible or non-compressible u g It Wlll alsobe apparent that while I have illustrated but two modifications of my invention,'various changes modifications, substitutions omissions an ,additions may be made without departing from the s irit and scope of the invention as set fort by the ap ended claims. v

f at I claim is:

ids as the lmpelling or the impelled medium.

1. In combination in -an apparatus of the character described, a diffuser, a chamber communicating, therewith, means for delivering-a jet of motive fluid through the d1 ffuser for translating medium contained 1n the chamber through the'difl'user, and movable means, within the difiuser, responsive to variations in the amount of medium to be translated for varyin the effective area of the throat of the di user.

2. In combinationin an apparatus of the character described, adifi'user, a chamber communicating with the difiuser, means for delivering, a jet of motive fluid through the difiuser for translating medium contained in the chamber through the difi'user, and movable'means within t efi'ective area of a portion of the difl'user.

3. In combination in an apparatus of the character described, a difl'user, a chamber communicating therewith, means for deliv ering a jet of motive fluid through the diffuser for translating medium from the e difi'user responsive to variations in the amount of medium to be translated from the chamber .for varylng the chamber through the diffuser, and a member movable in res onse to variations in the amount of me ium to be translated, for

varyin the effective area of a portion of the di user. a 4 y p 4. In combination in an a paratus of the character described, a cham er from which chamber,

fiuid medium is to be exhausted, a. diffuser communicating therewith, a nozzle-for delivering motive fluid into and through the and means located within the diffuser for varying the eflective area of the diffuser to compensate for variations in the amount of medium to be removed from said chamber- 7 5. In combination in an apparatus of the character described, a diffuser, a chamber.

communicating therewith, means for deliver- ,ing a jet of motive fluid through the diffuser for translating medium from the.

chamber throughthe difi'user, and a member movable in response to variations in the amount of medium to be translated, for

varying the eflective area of the difli'user and of the motive fluid delivery means. 7. An ejector comprising an inlet chamber, a converging-diverging tube communicating therewith, means for delivering motive fluid at high velocity to said tube, a

member located within the tube and formed to present a minimum resistance'to flow for varying the efiective area of the convergmgjdivergmg tube, and means responsive to variations in the operating pressure ratio of the ejector for controlling said member.

8. 'An-ejector comprising an inlet chamber, a converging-diverging tube communieating therewith, means for delivering motive for controlling said member,

undergoing compression in uid at high velocity to said tube, a"

member-formed to present aminimum resistin the operating pressure ratio of the ejector and means for preventing said means from responding to minor discontinuous variations in the pressure ratio. v

9. In combination in-an apparatus of the character described, a difiuserhaving means for varying the effective flow area of a portion of the diffuser.

- 10. In combination in' an apparatus of the character described, a difiuser having a means for effecting a coordination of the effective flow area of a portion of the diffuser and the amount of fluid flowing therethrough.

11. The processof ejecting consists in passing a motive fluid together with fluid entrained thereinthrough a diffuser, and in maintaining a normal ratio of compression in the difi'user under varying amounts of the fluid passing therethrough.

12. The process of ejecting a fluid which consists in passing a motive fluid together with fluid entrained therein through a \diffuser,- and in automatically stabilizing the flow of fluid through said difiuser.

, 13. The process of ejecting a fluid which consists in passing a motive fluid together with fluid entrained therein through a diffuser, -and in automatically stabilizing the compression of fluid in the difluser under a fluid which varying conditions of fluid flow therethrough. v

14. The process of ejecting a fluid which consists in compressing a fluid in a diffuser, and in automatically stabilizing the compression under varying amounts of fluid the difl'user- In testimony whereof, I have hereunto subscribed my name this 29th day of De- 'oember, 1921.

HENRY F. SCHMIDT. 

